Effect of Fabrication Techniques on the Properties of Carbon Nanotubes Reinforced Magnesium

2006 ◽  
Vol 111 ◽  
pp. 179-182 ◽  
Author(s):  
C.S. Goh ◽  
Jun Wei ◽  
L.C. Lee ◽  
Manoj Gupta
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Powder Metallurgy ◽  
Physical And Mechanical Properties ◽  
Strengthening Effect ◽  
Powder Metallurgy Technique ◽  
Reinforcement Effect ◽  
Similar Weight ◽  
Hybrid Reinforcement

In this study, both liquid and powder metallurgy techniques were employed to fabricate Mg nanocomposites. Comparisons were made on the physical and mechanical properties of Mg nanocomposites using these two different fabrication techniques. When similar weight fractions of carbon nanotubes (CNTs) were added to Mg using these two different techniques, the nanocomposites fabricated using powder metallurgy technique were found to be thermally more stable and has higher yield and tensile strengths than those produced using liquid metallurgy technique. The higher yield and tensile strengths were due to the presence of MgO particles which were pre-existent in the Mg powders. The MgO particles cause a hybrid reinforcement effect in the Mg-CNT nanocomposites, which surpasses the strengthening effect of the CNTs alone.

Characterization of Mg/MgO Nanocomposites Synthesized Using Powder Metallurgy Technique

Materials ◽  
2005 ◽  
Author(s):  
C. S. Goh ◽  
J. Wei ◽  
M. Gupta
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Volume Fraction ◽  
Physical And Mechanical Properties ◽  
Thermomechanical Analysis ◽  
Powder Metallurgy Technique ◽  
Magnesium Matrix ◽  
Individual Particles ◽  
Threshold Amount

Magnesium nanocomposites with 0.1, 0.2, 0.3 and 0.4 volume percentages of MgO were synthesized using the powder metallurgy technique. The nanocomposite billets obtained were subsequently hot extruded at a temperature of 350 °C with an extrusion ratio of 20.25:1. The extruded nanocomposites were characterized for their microstructural, physical and mechanical properties. The microstructures of the nanocomposites showed individual particles of MgO uniformly distributed in the magnesium matrix. The thermomechanical analysis results revealed that a more thermally stable magnesium nanocomposite could be obtained with a threshold amount of MgO. The tensile properties results indicated that the yield strength peaks at 0.3 vol.% of reinforcement incorporated, with an improvement of approximately 17%. An attempt is made to correlate the volume fraction of the MgO with the resultant physical and mechanical properties of the magnesium nanocomposites.

Influence of Carbon Nanotubes on the Physical and Mechanical Behaviours of Magnesium

2005 ◽  
Author(s):  
C. S. Goh ◽  
J. Wei ◽  
M. Gupta
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Physical And Mechanical Properties ◽  
Thermomechanical Property ◽  
Powder Metallurgy Technique ◽  
Weight Percentage ◽  
Mechanical Behaviours ◽  
Property Characterization ◽  
Work Of Fracture ◽  
Thermal Stability Of

The powder metallurgy technique was used to synthesize magnesium reinforced with up to 0.3 weight percentage of carbon nanotubes (CNTs). The nanocomposites fabricated were extruded at an extrusion ratio of 20.25:1 and then characterized for their physical and mechanical properties. The influences of carbon nanotubes on the physical and mechanical properties of Mg were investigated. The thermomechanical property characterization shows an increase in thermal stability of the Mg nanocomposites with increasing amount of CNTs added. Mechanical property results reveal an improvement in yield strength, ductility and work of fracture with higher weight percentages of CNTs incorporated. An attempt is made to correlate the physical and mechanical properties with the increasing weight fractions of carbon nanotubes in pure Mg matrix.

The Influence of Carbon Addition on the Physical and Mechanical Properties of WC-Co Sintered Powders

2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Ahmad Aswad Mahaidin ◽  
Mohd Asri Selamat ◽  
Samsiah Abdul Manaf ◽  
Talib Ria Jaafar
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Powder Metallurgy ◽  
Grain Growth ◽  
Rupture Strength ◽  
Physical And Mechanical Properties ◽  
Cobalt Content ◽  
Powder Metallurgy Technique ◽  
Densification Process ◽  
Carbon Addition

The mechanical properties of WC-Co are highly dependent on its cobalt content, density and grain size of the WC particles. Addition of free carbon during the consolidation of process is said to improve the densification process and inhibit grain growth. However, there are still plenty of works needs to be done regarding this matter to support the fact. Therefore, this study is to evaluate the effect of carbon addition on the physical and mechanical properties of WC-Co-C sintered powders. The WC-Co-C sample is fabricated using powder metallurgy technique, in which the powders were uniaxially pressed at 625 MPa and cold-isostatic pressed at 200 MPa. Then, the sample is sintered in nitrogen-based atmosphere at temperature range of 1350-1450C. The physical and mechanical properties of the WC-Co sintered powders were analysed. It is found that WC-Co-C has a relatively higher density and hardness but exhibit lower transverse rupture strength compared to WC-Co.

Development of Mg/Cu Nanocomposites Using Microwave Assisted Powder Metallurgy Technique

Materials ◽  
2005 ◽  
Author(s):  
W. L. E. Wong ◽  
M. Gupta
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Physical And Mechanical Properties ◽  
Microstructural Characterization ◽  
Radiant Heat ◽  
Powder Metallurgy Technique ◽  
Microwave Assisted ◽  
The Matrix ◽  
Rapid Sintering ◽  
Nano Size

In the present study, magnesium composites containing different amount of nano-size copper particulates were successfully synthesized using powder metallurgy technique coupled with a novel microwave assisted rapid sintering. Mg/Cu nanocomposites were sintered using a hybrid heating method consisting of microwaves and radiant heat from external susceptors. The sintered specimens were hot extruded and characterized in terms of microstructural, physical and mechanical properties. Microstructural characterization revealed minimal porosity and the presence of a continuous network of nano-size Cu particulates decorating the particle boundaries of the metal matrix. Mechanical characterization revealed that the addition of nano-size Cu particulates lead to an increase in hardness, 0.2% yield strength (YS) and ultimate tensile strength (UTS) of the matrix. An attempt is made in the present study to correlate the effect of increasing presence of nano-size Cu reinforcement on the microstructural, physical and mechanical properties of monolithic magnesium.

scholarly journals Role of carbon and nitrogen in the improvement of corrosion resistance of new powder metallurgy Co-Cr-Mo alloys

2020 ◽  
Vol 38 (3) ◽  
pp. 273-286 ◽  
Author(s):  
Cristina Garcia-Cabezon ◽  
Celia Garcia-Hernandez ◽  
Maria L. Rodriguez-Mendez ◽  
Gemma Herranz ◽  
Fernando Martin-Pedrosa
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Powder Metallurgy ◽  
Nitrogen Content ◽  
Powder Metallurgy Technique ◽  
Carbon And Nitrogen ◽  
Physiological Conditions ◽  
Carbon And Nitrogen Content ◽  
Astm F75

AbstractMicrostructural changes that result in relevant improvements in mechanical properties and electrochemical behavior can be induced using different sintering conditions of ASTM F75 cobalt alloys during their processing using powder metallurgy technique. It has been observed that the increase in carbon and nitrogen content improves corrosion resistance and mechanical properties as long as the precipitation of carbides and nitrides is avoided, thanks to the use of rapid cooling in water after the sintering stage. In addition, the reduction of the particle size of the powder improves hardness and resistance to corrosion in both acid medium with chlorides and phosphate-buffered medium that simulates the physiological conditions for its use as a biomaterial. These results lead to increased knowledge of the role of carbon and nitrogen content in the behavior displayed by the different alloys studied.

scholarly journals Fabrication and Characterization of Polylactic Acid Electrospun Scaffolds Modified with Multi-Walled Carbon Nanotubes and Hydroxyapatite Nanoparticles

Biomimetics ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 43
Author(s):  
Athanasios Kotrotsos ◽  
Prokopis Yiallouros ◽  
Vassilis Kostopoulos
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Polylactic Acid ◽  
Physical And Mechanical Properties ◽  
Polymeric Materials ◽  
Cost Effective ◽  
Electrospinning Process ◽  
Wide Range ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The solution electrospinning process (SEP) is a cost-effective technique in which a wide range of polymeric materials can be electrospun. Electrospun materials can also be easily modified during the solution preparation process (prior SEP). Based on this, the aim of the current work is the fabrication and nanomodification of scaffolds using SEP, and the investigation of their porosity and physical and mechanical properties. In this study, polylactic acid (PLA) was selected for scaffold fabrication, and further modified with multi-walled carbon nanotubes (MWCNTs) and hydroxyapatite (HAP) nanoparticles. After fabrication, porosity calculation and physical and mechanical characterization for all scaffold types were conducted. More precisely, the morphology of the fibers (in terms of fiber diameter), the surface properties (in terms of contact angle) and the mechanical properties under the tensile mode of the fabricated scaffolds have been investigated and further compared against pristine PLA scaffolds (without nanofillers). Finally, the scaffold with the optimal properties was proposed as the candidate material for potential future cell culturing.

scholarly journals Wide-Gap Brazing of K417G Alloy Assisted by In Situ Precipitation of M3B2 Boride Particles

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3140 ◽  
Author(s):  
Zhun Cheng ◽  
Xiaoqiang Li ◽  
Minai Zhang ◽  
Shengguan Qu ◽  
Huiyun Li
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Room Temperature ◽  
Distribution Characteristics ◽  
Powder Metallurgy Technique ◽  
Dispersion Strengthening ◽  
Eutectic Transformation ◽  
Wide Gap ◽  
Strength And Plasticity

In this study, K417G Ni-based superalloy with a 20-mm gap was successfully bonded at 1200 °C using powder metallurgy with a powder mixture. The results indicated that the microstructure and mechanical properties of the as-bonded alloy were highly dependent on the brazing time (15–45 min), mainly due to the precipitation and distribution characteristics of M3B2 boride particles. Specifically, alloy brazed for 30 min exhibited desirable mechanical properties, such as a high tensile ultimate strength of 971 MPa and an elongation at fracture of 6.5% at room temperature, exceeding the balance value (935 MPa) of the base metal. The excellent strength and plasticity were mainly due to coherent strengthening and dispersion strengthening of the in situ spherical and equiaxed M3B2 boride particles in the γ + γ′ matrix. In addition, the disappearance of dendrites and the homogenization of the microstructure are other factors that cannot be excluded. This powder metallurgy technique, which can avoid the eutectic transformation of traditional brazing, provides a new effective method for wide-gap repair of alloy materials.

Evaluation of the Influence of Pre-Alloyed Powder Fe65Nb on the Production of Metal Matrices by Powder Metallurgy

2020 ◽  
Vol 1012 ◽  
pp. 3-8
Author(s):  
A.C.G. Silva ◽  
Hellen C.P. Oliveira ◽  
Thales Eduardo Leal ◽  
Paulo Santos Assis
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Chemical Composition ◽  
Solid State ◽  
Hot Pressing ◽  
Physical And Mechanical Properties ◽  
Toxic Element ◽  
Alloyed Powder ◽  
Eds Analysis ◽  
Porosity Measurements

The objective of this paper is to study Fe65Nb-Cu metal matrices, thus varying the content of the pre-alloyed Fe65Nb powder from 10% to 100%. Therefore, powders of Fe65Nb and Cu were used, innovating in the chemical composition of the commonly used matrices. The objective is to evaluate the substitution of Co (toxic element, commonly used) by Nb (98.2% of reserves are Brazilian). For the sintering of the samples it was used hot pressing technique. The parameters were set at: 850°C / 35MPa / 3min. The sintered bodies underwent SEM/EDS analysis and density and porosity measurements were performed. From the results it is possible to say that the compositions of (10% and 30% Fe65Nb) presented the best physical and mechanical properties. The relative density decreases for the compositions with 40%, 50% and 60% Fe65Nb is justified by the presence of fragile particles in metal matrices, since they require more energy in order to efficiently transport matter (diffusion) in a solid state.

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